Volumetric ultrasound scanning of the breast can serve as a complementary modality for breast cancer screening as described, for example, in the commonly assigned US 2003/0007598A1 and US 2003/0212327A1, each of which is incorporated by reference herein. Whereas a conventional two-dimensional x-ray mammogram only detects a summation of the x-ray opacity of individual slices of breast tissue over the entire breast, ultrasound can separately detect the sonographic properties of individual slices of breast tissue, and therefore may allow detection of breast lesions where x-ray mammography alone fails. Another well-known shortcoming of x-ray mammography practice is found in the case of dense-breasted women, including patients with high content of fibroglandular tissues in their breasts. Because fibroglandular tissues ha+ve higher x-ray absorption than the surrounding fatty tissues, portions of breasts with high fibroglandular tissue content are not well penetrated by x-rays and thus the resulting mammograms contain reduced information in areas where fibroglandular tissues reside. Still another shortcoming of x-ray mammography practice relates to difficulty in imaging near the chest wall, because it is difficult to extend these tissues outward onto the compression plates for proper imaging. A substantial number of cancers are known to occur within 3 cm of the chest wall, which can thereby be missed by x-ray mammography.
In addition to being useful as a complementary modality to x-ray mammography, ultrasound mammography could well become a sole breast cancer screening modality for at least some patient groups. For example, it is believed that preventive health care policy will progress toward the adoption of regular breast cancer screening procedures for increasingly younger women, e.g., women under the age of 40, and perhaps even under the age of 30 if there is a family history of cancer. Because younger women generally have denser breasts, the shortcomings of conventional two-dimensional x-ray mammography are expected to become especially apparent. Even further, because the dangers of x-ray radiation exposure are cumulative over a lifetime, ultrasound mammography could well become a sole breast cancer screening modality for women in these younger age groups. Other demographics indicating higher breast densities among certain groups, regions, or countries may also lead to the increased adoption of breast ultrasound as a sole or adjunctive screening modality for those groups, regions, or countries.
Once a thorough set of breast ultrasound scans is obtained, a challenge arises in the context of processing and displaying the breast ultrasound information to a clinician. In general, there is an inherent tension between (i) promoting high sensitivity/specificity in the screening and/or diagnosis process, and (ii) promoting efficient patient throughput to keep costs manageable. Thus, for example, while careful slice-by-slice scrutiny of the raw ultrasound scans by a well-trained radiologist would promote high sensitivity and specificity, the overall workflow efficiency of this method would be low, and therefore costs would be high, in view of the hundreds of individual raw ultrasound slices to be reviewed for each patient.
Accordingly, it would be desirable to provide an interactive user interface for viewing breast ultrasound information that can be effective for (i) adjunctive ultrasound mammography environments in which the ultrasound information complements x-ray mammogram information, and/or (ii) ultrasound-only mammography environments in which ultrasound is a sole screening modality.
It would be further desirable to provide processing and display of breast ultrasound information in a manner that promotes high specificity and sensitivity in the breast cancer screening and/or diagnosis process.
It would be still further desirable to provide such processing and display of breast ultrasound information while also promoting high patient throughput and low per-patient costs in the breast cancer screening and/or diagnosis process.
It would be even further desirable to provide such processing and display of breast ultrasound information that is effective for a wide variety of breast sizes, including smaller-sized breasts.
It would be still further desirable to provide an interactive user interface for an ultrasound mammography system that allows the radiologist to quickly and intuitively navigate among different representations of the breast ultrasound information.
It would be even further desirable to provide such processing and display of breast ultrasound information that is effective in exposing breast abnormalities that are in close proximity to the chest wall of the patient, where a comparatively high percentage of breast abnormalities arise.